A cooling system can comprise a closed system that uses a refrigerant to cool the air in proximity to the cooling system. For example, most late model vehicles comprise an air conditioning system to cool air within a portion of the vehicle, such as a passenger compartment of an automobile or a storage area of a refrigerated van. In some instances, a refrigerant must be removed from the cooling system during service. A refrigerant recovery system (RRS) can be used to remove the refrigerant from the cooling system. The RRS can comprise a refrigerant storage tank (RST) to store the refrigerant removed from the cooling system. The RRS can be used to recharge the cooling system with the refrigerant stored in the RST. The RST occasionally needs to be filled with a refrigerant from a refrigerant supply that is not part of a cooling system. Some RRS comprise a scale to measure the weight of refrigerant within the RST to prevent overfilling the RST. Adjusting the refrigerant scale of an RRS automatically would remove the burden of a user having to determine whether the scale needs to be adjusted and remove the burden of having to adjust the refrigerant scale, assuming the refrigerant scale is adjustable.